Apparatus for making structural reinforcement preforms including energetic basting of reinforcement members

ABSTRACT

A rigid three-dimensional preform is made by moving a plurality of webs of fibrous reinforcement material superposed and coplanar to a cutter, the webs being coated with an electromagnetic energy-curable binder and pressed together. Prior to cutting a blank in a two-dimensional development of the three-dimensional preform from the webs, the webs are tacked together at spaced local zones by locally curing the binder at those zones by locally applying the appropriate electromagnetic radiation (microwave, ultraviolet, electron) so that the webs travel as one to the cutter. After cutting of the blank, the blank is loaded into a mold to replicate the three-dimensional shape of the preform and the remainder of the binder is cured in the mold by the application of the appropriate electromagnetic radiation. An auxiliary member may be attached to the preform by applying an electromagnetic energy-curable binder to at least one location on the preform, moving the auxiliary member into a desired position and intimate contact with the binder-coated location and the binder cured at that location by the application of the appropriate electromagnetic radiation.

This is a division of application Ser. No. 07/552,253, filed Jul. 12,1990, now U.S. Pat. No. 5,217,656.

CROSS REFERENCE TO RELATED APPLICATION

This application is related to our application Ser. No. 446,859, filedDec. 6, 1989.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and to an apparatus for makingstructural reinforcement preforms for resin transform molding (RTM) andreaction injection molding (SRIM) processes for structural composites,and is further particularly concerned with the handling of reinforcementwebs used in the process and in attaching reinforcement members and thelike as a part or parts of the preforms.

2. Description of the Prior Art

As set forth in our aforementioned patent application Ser. No. 446,859,filed Dec. 6, 1989, in making preforms according to the directed fiberprocess, it has heretofore been the practice to spray chopped fiberswith a binder resin onto a form that has air pulled therethrough tolocate and hold the fibers in place. The form with the fibers and thebinder resin thereon is then moved into a hot air plenum chamber, driedand/or cured to set the binder resin. In addition, a great deal ofprocessing space is required for drying, curing and cooling thepreforms.

In making thermoformed preforms, it is heretofore been the practice touse a continuous strand fiber mat that has been previously coated by thefiber manufacturer with a thermoplastic binder. The thermoformable matis supplied in a roll form whereby it is unrolled into flat sheets ofvaried layer thicknesses and clamped into a holding frame at the edges.The frame network is then positioned in an oven chamber containingradiant heaters which slowly heat the reinforcement mat and thethermoplastic binder from both sides. Upon heating, the thermoplasticbinder softens and, while soft, the frame network is quickly transferredinto a cold mold. The mold closes via a press forcing the reinforcementmat into the desired shape of a part. Upon cooling, the thermoplasticbinder stiffens and thus holds the thermoformable mat in its new shape.

As pointed out in our aforementioned patent application, Serial No.446,859, these processes are slow, require a great deal of space and alarge amount of energy.

As also pointed out, in conventional RIM/SRIM process applications forstructural components, fiber layer thickness across the entire preformis increased to meet the strength requirements of one area, whichresults in unnecessary use of material in other areas and increasesthickness and weight. Furthermore, neither the directed fiber processnor the thermoformable mat process allows a designer to add ribs orclosed sections to maximize design properties.

In our aforementioned application, therefore, we proposed a new systemwhich eliminates the necessity for large rooms and constantly operatingovens, cooled presses and the like and permits design flexibility withrespect to the provision of reinforcement ribs, close sections, andreinforcement and/or attachment members while at the same time saving onenergy and materials.

Our new process, as disclosed in application Ser. No. 446,859, utilizesspecifically-developed binders along with directed energy systems forrigidizing the composite forms and attaching structural components tothe preforms and is entirely compatible with RTM and SRIM resin systems,i.e. polyesters, vinyl esters, urethanes, epoxies, phenolics andacrylics. The process is designed to be fully automated and to enablespecific distribution and placement of numerous type of reinforcements,where necessary, for the required structural properties of a preform.There is a complete freedom of design inherent in the process and allowsfor the most desirable reinforcement type and/or structures includingclosed structural shapes and varied wall sections to meet designcriteria.

In the process disclosed in the aforementioned application, mats ofreinforcement material are cut into a desired shape as a two-dimensionalplanar development of a desired preform. The cut mats are then coatedwith a binder which is responsive to electromagnetic energy, eithermicrowave radiation or ultraviolet radiation, and the cut mats areplaced in a three-dimensional mold and pressed to replicate the desiredshape of the preform.

While in the mold, the coated and shaped mats are subjected to theappropriate electromagnetic radiation, either microwave or ultravioletradiation, to cure the binder resin and provide rigidity in a matter ofseconds, rather than minutes or hours as with the heat-curableprocesses. At this point, the preform is a finished product for use in afurther molding operation (RTM, SRIM) or may be viewed as a carrierpreform for the attachment of structural reinforcement members and thelike before being used in a further molding operation (RTM, SRIM).

As a carrier preform, the rigid three-dimensional preform is removedfrom the mold to a station where a designated area or areas of thepreform or of a subassembly (reinforcement rib) are provided with afurther coating of an electromagnetic energy curable binder resin, thesubassembly (reinforcement member or the like) is moved into intimatecontact with the preform at the coated area or areas and the appropriateelectromagnetic radiation is applied to energetically stitch (cure thebinder) the subassembly to the carrier preform. When the finalattachment has been made by such energetic stitching, the preform is afinished product in itself ready for use as a structural reinforcementpreform as a part of a further molding process for making a structuralcomposite.

As a structural reinforcement preform the structure is hollow as thewalls are permeable to the pressure-applied material during RTM/SRIMprocessing so that any pocket or chamber could fill with the plasticmolding material causing waste, increased weight and longer curing time.Therefore, a core may be inserted in any such pocket or chamber toprevent or at least minimize such an event. The core may be held inplace by a subassembly (cover) energetically stitched to the preform.

We have determined that the entire process may be improved, particularlywith respect to the handling of the reinforcement material prior tobonding in that a plurality of layers of reinforcement material must beindividually cut into the desired shape and individually stacked inregistry in the mold. With such layers tacked together prior to cutting(termed energetic basting), so that the cut layers are essentially asingle element,-handling is simplified in that registration of thelayers is then inherent.

We have also determined that the binder can be applied and the layerstacked together, prior to cutting, so that there is no necessity oflater applying binder resin to individual layers after cutting.

We have also determined that the layers of reinforcement material may bedrawn as webs from roll goods, the binder resin applied and the webssuperposed and tacked together (energetically basted) at spaced localzones prior to cutting by selective curing of such zones with theremaining uncured binder resin available for later curing and rigidizinga shaped element in the mold.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to provide animproved method and apparatus for making rigid three-dimensionalpreforms in which the initial material handling and manipulation aredifferent from and simplified with respect to those heretofore known, inwhich the mats of cut shapes for molding into a rigid three-dimensionalform are tacked together and handled as a single mat, and in which thetacking of the webs together is accomplished, prior to cutting, byenergetic basting of spaced local zones of superposed webs carrying anelectromagnetic energy-curable binder resin, with the remaining uncuredbinder resin outside of the zones available for later use in thethree-dimensional molding process.

Another object of the invention is to provide for the energeticstitching of reinforcement members to the inside and/or outside of thehollow three-dimensional preforms and including the provision of a coverfor such a hollow preform, these elements being attached by energeticstitching.

Another object of the invention is to provide for robotic handling ofthe cut mats and of the preforms and reinforcement elements at therespective locations prior to and after the molding and curing of thepreforms.

The above objects are achieved, according to the present invention, in aprocess in which webs of reinforcement material, such as glass fibermaterial, are unrolled from roll goods of such material and guidedsuperposed to a pressing or compaction device. Between the supply ofroll goods and the pressing or compaction device, at least one surfaceof each pair of facing surfaces of the superposed webs has anelectromagnetic energy curable binder resin applied thereto, as byspraying. In the pressing or compaction device the superposed layers arepressed together to spread and permeate the binder resin into the websand into greater contact with the fibers thereof. The webs then movesthrough an energetic basting station where the appropriateelectromagnetic energy is applied thereto at selected spaced locationsso as to cure the binder resin at corresponding selected spaced zonesthrough the multilayer structure thereby basting or tacking the webstogether while leaving large areas or zones of remaining uncured binderresin for subsequent curing during the molding process. Next, thesuperposed and basted webs are moved to a net shape pattern cuttingstation at which the multilayer structure is cut into a desired shapewhich is a two dimensional planar development of the three-dimensionalpreform. The basting head may also be mounted with the cutting heat andcyclically operated to baste during the cutting process. After cutting,the individual cut mats are picked up by a robot and positioned on amold plug of the male half of a mold which has a complementary moldcavity in a female half of the mold. The mold is then closed to pressthe mat into the desired three-dimensional shape of the preform and themold is then energized with the appropriate electromagnetic energy tocure the remaining binder resin and rigidize the shaped mat into thedesired rigid three-dimensional preform.

As mentioned in our aforementioned patent application, Ser. No. 446,859,the mold may comprise in each of its male and female parts, half of ajoinable waveguide for directing microwave energy to cure the binderresin. Alternatively, each half of the mold may include an ultravioletlamp or lamps for curing ultraviolet responsive binder resins. In thiscase, the mold is constructed, at least at its facing mold surfaces, asa wire screen or from an ultraviolet transmissive material, such as aclear acrylic which does not contain ultraviolet blockers.

After molding, the rigidized three-dimensional preform is removed fromthe mold and manipulated by robotic devices as a carrier preform for theattachment of reinforcement members. In this part of the process, thecarrier preform is oriented to a desired position, a surface area orareas thereof is or are sprayed with a binder resin, such as anultraviolet curable binder resin, a reinforcement rib or the like ismoved into intimate contact with the sprayed area or areas and thesprayed area or areas is or are then illuminated with electromagneticenergy, here ultraviolet energy, to cure the binder resin. The curedbinder resin bonds the reinforcement member to the carrier preform. Thisattaching of reinforcement members, termed energetic stitching, may takeplace several times to provide reinforcement ribs inside thethree-dimensional shape, outside the three dimensional shape on theouter surface thereof and/or to add a cover which closes the hollowthree-dimensional structure.

After the final reinforcement member is attached, the preform may bestored or moved to a molding station of an RTM or an SRIM moldingprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention, itsorganization, construction and operation will be best understood fromthe following detailed description, taken in conjunction with theaccompanying drawings, on which:

FIG. 1 is an elevation view of the processing stations of one embodimentof an entire preform making process;

FIG. 2 is a somewhat more detailed perspective view of the reinforcementmaterial supply, binder application and compaction portions of thesystem of FIG. 1;

FIG. 3 is a somewhat more detailed view of the process, shown inperspective, from the output of the compaction device and including, inparticular, one embodiment of the energetic basting structure;

FIG. 4 is a sectional view taken through an energetic basting location;

FIG. 5 is a somewhat exploded view of three webs which have undergoneenergetic basting;

FIG. 6 is a perspective view of another portion of the process of FIG. 1showing the pattern cutting structure;

FIG. 7 is a perspective view of another portion of the process of FIG. 1showing, in particular, the molding apparatus receiving a cut blank fromthe cutting apparatus;

FIG. 8 is a perspective view showing the mold in a closed condition withthe cut blank formed into the desired shape;

FIG. 9 is a perspective view, shown partially cut away, similar to FIG.8 and further illustrating the provision of high-intensity ultravioletradiation;

FIG. 10 is a perspective view showing the mold in an open condition withthe rigid shaped preform removed from the mold and ready for transportfor subsequent processing;

FIG. 11 is a perspective view of a portion of the process of FIG. 1illustrating one embodiment of energetic stitching of an outerreinforcement rib to the preform of FIG. 10 by ultraviolet techniques inwhich the binder is applied to the preform; alternatively it could beapplied to the rib;

FIG. 12 is a view of energetic stitching apparatus similar to that ofFIG. 11, but showing the energetic stitching of an internalreinforcement rib by ultraviolet techniques;

FIG. 13 is another perspective view of energetic stitching apparatus,similar to that of FIGS. 11 and 12, showing the energetic stitching ofan elongate internal longitudinal reinforcement rib by ultraviolettechniques;

FIG. 14 is a view similar to that of FIG. 13 and showing the energeticstitching of the elongate internal reinforcement rib by way of microwavetechniques;

FIG. 15 is a perspective view of another embodiment of energeticstitching using microwave techniques showing the addition and stitchingof a cover for closing the hollow preform;

FIG. 16 is a perspective view of another embodiment of energeticstitching apparatus using ultraviolet energy for attaching the cover tothe preform;

FIG. 17 is a perspective view, again beginning at the output of thecompaction device, showing another embodiment of the invention in whichthe energy for energetic basting may be generated by a high-intensityultraviolet generator or an electron beam gun; and

FIG. 18 is a perspective view of another embodiment of the inventionbeginning at the output of the compaction stage and illustratingenergetic basting apparatus in which the energy for energetic basting issupplied by a microwave generator and directed and focused by a splitwaveguide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a process for making rigid three-dimensionalpreforms is illustrated as comprising a plurality of process stations orstages 1-10.

At the supply stage 1, a plurality of rolls of reinforcement material,such as glass fiber continuous strand, chopped strand, woven fabric mator the like is mounted for dispensing a like plurality of webs of thematerial superposed with respect to one another toward a compactionstage 3 where the webs are received, guided and directed coplanar withrespect to one another.

Between the supply stage 1 and the compaction stage 3 is a binderapplication stage 2 in which an electromagnetic radiation-curable binderresin is applied to at least one surface of each pair of facing surfacesof the webs. Here, the binder may be applied to the upper and lowersurfaces of the middle web, but may also be applied to the lower surfaceof the upper web and the upper surface of the lower web or to all of thefacing surfaces.

In the pressing or compaction stage 3, the webs are pressed togethercausing spreading of the binder and permeation of the binder intogreater contact areas with the fibers of the webs.

The superposed webs are then fed to an energetic basting station 4 wherethey are basted or tack welded together at locations spacedlongitudinally and transversely of the webs. These spaced locations, aswill hereinafter be described, are also considered to be basting zonesin that they are three-dimensional and extend to and bind all of thewebs.

The webs, basted together to form essentially a single element, are thenmoved to a net shape pattern cutting stage 5 in which a two-dimensionalplanar projection or planar development of the three-dimensional desiredstructure is cut from the web for later forming into thethree-dimensional shape of the preform. The shape cut from themultilayer web is hereinafter called a mat and is transferred to a moldstage 7 by way of a material pickup stage 6. At the mold stage 7, themat is positioned between separable parts of a mold which is then closedcausing the mat to assume the contours, i.e. shape, of thethree-dimensional preform. At the mold stage 7 and while still in themold, the shaped mat is subjected to electromagnetic radiation of a typeto which the binder resin is sensitive to cure. Upon curing, the shapedmat becomes rigid and is transformed into a rigid three-dimensionalpreform. Upon opening of the mold, the preform may be removed from themold stage 7 and transferred to an energetic stitching stage 9 by way ofa material handling stage 8, that is if the preform is to be considereda carrier preform for the attachment of reinforcement members or thelike. If not, the material handling stage 8 may simply deposit the rigidthree-dimensional preform on a conveyor 10 for discharge for storage orfor transport to, for example, a resin transfer molding (RTM) process ora reaction injection (SRIM) molding process.

If the preform is to assume the status of a carrier preform, thematerial handling stage 8 may operate in conjunction with theelectromagnetic stitching stage 9 to manipulate the preform intopositions as hereinafter described.

In the electromagnetic stitching stage 9, reinforcement members areattached to the carrier preform by spraying an electromagnetic-sensitivebinder, as indicated at 104 onto specified locations of the carrierpreform and/or the subassembly, the reinforcement rib moved into adesired orientation and into intimate contact with the locations by amaterial handling device 128 and the locations subjected toelectromagnetic radiation by way of an electromagnetic stitching source96.

There may be a plurality of the material handling devices 128, asneeded, in order to handle and stitch a plurality of reinforcementmembers to the carrier preform.

As indicated on FIG. 1, the material handling stages may comprise aplurality of robots 74, 94, 128 and 105, of which the robot 105 formoving the spray device 104 is symbolically illustrated as connectedthereto by mechanical linkage shown by broken lines. Inasmuch asrobotics and robotic devices are well known in the art, a detailedexplanation thereof is not considered necessary here.

It will be appreciated that the above-described process is continuousand describes a stepped process cycle in which the processing stage withthe longest processing time is the controlling stage. Inasmuch asshaping and rigidizing the preform is only a matter of seconds, it isassumed that for most processes, this is not the controlling stage.Depending on the number of reinforcement members added and the nature ofthe shape of the cut pattern, either of these stages could be consideredthe controlling stage by which all other processing times and the timingthereof are determined and tailored to the following molding process.

Referring to FIG. 2, a more detailed view of the supply stage 1, thebinder application stage 2 and the compaction stage 3 is illustrated.The supply stage 1 is illustrated as comprising a plurality of rolls12-16 of reinforcement material which are to be dispensed as individualwebs in a superposed relation toward a predetermined location at thebeginning of the compaction stage 3 at which the webs are aligned totravel coplanar with respect to one another. This is accomplished by apair of opposed press rollers 30 and 32.

The binder resin spray applicator 2 is illustrated as comprising spraymechanisms 18 and 20 which are fed from a reservoir 28 by way of a pump26 to provide a mist or cloud 22, 24 between the upper web 12 and thecenter web 14 and between the center web 14 and the lower web 16. Thebinder spray coats at least one of the facing surfaces of each pair offacing surfaces with binder resin.

As the superposed webs move through the compaction stage 3, pairs ofopposed press rollers 30 and 32; 34 and 36; 38 and 40 press the webstogether and spread the binder resin for permeation into the webs and toenlarge the contact area thereof with the fibers of the webs.

Referring to FIG. 3, the coplanar multilayer web structure isillustrated as exiting the compaction stage 3 between the press rollers38 and 40 and entering the energetic basting station 4.

The energetic basting station 4 comprises a gantry 42 including a member48 which may be driven transversely above the webs on a beam 50, amember 52 which may be moved with respect to the member 48 in thedirection of movement of the webs and opposite thereto, a member 56carried in cantilever fashion at an end of the member 52 and a member 54which may be driven perpendicular to the webs through the member 56, themember 54 supporting a source, here an ultraviolet source 44 whoseultraviolet emission is conducted by way of a fiber optic ultravioletwand 46 toward the upper surface of the webs to cause penetration of theultraviolet light at a plurality of spaced locations 47. The source maybe periodically activated or its emission may be periodically gated toprovide curing at spaced zones in the longitudinal direction of thewebs. The driving and driven members may include rack and pinion typestructures.

Turning to FIGS. 4 and 5, a fiber optic wand 46 is illustrated in FIG. 4as directing ultraviolet radiation toward a location 47 and thereatpenetrating through the three webs 12, 14 and 16. The binder applied inFIG. 2 by way of the clouds 22 and 24 is illustrated with the samereference characters in FIG. 4 as being between the webs and penetratedby the ultraviolet radiation which cures the binder resin 22 and 24 inrespective zones 58 and 60 to bind the webs together at the spacedlocations 47. The same bound structure is illustrated in FIG. 5 with thezones 58 and 60 indicated as strands connecting the webs together.Actually, however, the webs are as one at these locations.

Referring to FIG. 6, the basted webs are illustrated as having movedinto the net pattern cutting stage 5 where they are cut into bastedmultilayer mats or blanks B. The cutting stage 5 may comprise a gantry62 including a transverse member 68 which is mounted for movementlongitudinally of the webs on a member 66 which is supported by a table64 (FIG. 1). A member 70 is movable transversely on the member 68 andcomprises a device for cutting the multilayer webs into the desiredshapes. The gantry 62 and the device 70 therefore constitute an X-Ypattern cutter which is effective to cut the desired shapes for the matsor blanks B by way of a cutter 72 which may be constituted, for example,by a knife or a laser beam. As mentioned above, the basting head may bemounted on the gantry 62 and periodically operated to baste the webstogether.

As indicated above, the driving structures for the elements 48-56 ofFIG. 3 and 64-70 of FIG. 6 may be electric motors with rack and pinionoutput structures or any other suitable devices for providing X, Y, Zor, respectively, X-Y movements.

The cut blanks B are removed from the cutting stage 5 by the materialpick up apparatus 74 of the material handling stage 6 and positioned inthe mold stage 7. This is shown in greater detail in FIG. 7 in which acut blank B has been positioned over a lower shaping mold 86 whichincludes a male mold plug 90 and which is below and in registry with anupper shaping mold 82 which includes a female mold cavity 88 generallyconforming to the shape of the male mold plug 90. As shown, anotherblank B is being cut at the cutting station 5 and the robot 74 hasreturned to handle that next blank B.

The mold is then closed by operating the ram 84 to lower the crossbar 80and the upper mold 82 to mate the upper and lower shaping mold parts, asshown in FIG. 8, so that the blank B now assumes the character of athree-dimensional shaped element S which conforms to the desired shapeof the rigid three-dimensional preform.

While the mold is closed, and as specifically illustrated in FIG. 9, theshaped element S is subjected to electromagnetic radiation, here in theform of high-intensity ultraviolet radiation to cure the remainingbinder resin which was not cured during energetic basting at theenergetic basting stage 4. In order to provide the ultravioletradiation, at least the facing walls of the molds 82 and 86 are formedwith an ultraviolet transmissive material, such as a wire grid or aclear acrylic. In addition to the single lamp 92 illustrated in FIG. 9,a plurality of such lamps may be provided in the male mold plug and/orperipherally about the female mold cavity. After curing, the moldedelement is a rigid three-dimensional preform P which may be moved fromthe mold stage 7 and deposited on the conveyor 10 to transport the samefor storage or for use in a further molding process as set forth above.

Referring to FIGS. 1 and 10, in order to remove the preform P, the ram84 is operated to raise the crossbar 80 and the upper mold 82 toseparate the mold 82 from the mold 86. The robot 94 may then pick up thepreform P, as illustrated in FIG. 10, to move the preform P either tothe conveyor 10 or to the energetic stitching station 9.

Assuming that the preform P is now considered to have the status of acarrier preform, the preform P is moved to the energetic stitching stage9 (FIG. 1). At this station, the robot 94 of the material handling stage8 may hold the preform P in the position illustrated in FIG. 11. Whilein this position, a robot 105 manipulates a binder applicator 104 tospray and electromagnetic energy-curable binder on an area 102 at alocation at which an external reinforcement rib ER is to be attachedand/or on the matching surface of the reinforcement rib. Then, a robot128 (FIG. 1) or another suitable manipulator orients the member ER intoposition transversely of the preform P and into intimate contact withthe sprayed area 102. Then, a robot 96 positions an electromagneticstitcher into place which in FIG. 11 is constituted by an ultravioletgenerator 98 for producing an ultraviolet beam 100, and to direct thesame onto an area 106 or, preferably, a plurality of such areas alongthe rib ER, to cure the binder thereat and energetically stitch the ribER to the preform P.

The robot 94 may then rotate the preform P 180° and the same steps thenperformed for an internal reinforcement rib IR to energetically stitchthe same with the cavity of the carrier preform P. As shown in FIG. 12,this is an almost identical operation to that shown in FIG. 11 for theexternal rib ER. The robot gantry 96 may be moved, in either case, toscan along the length of the rib and energetically stitch the respectiverib to the carrier preform at a plurality of the locations 106.

Alternatively or in addition to the internal rib IR being applied, therobot 105 may manipulate the binder spray device 104 to spray anelongate area along the inner surface of the carrier preform P and/or amatching surface of the internal rib IR. In this case, the robot 128 orsimilar manipulator picks up and moves an appropriate shaped elongateinternal reinforcement member LIR into intimate contact with the preformP at the sprayed area and the ultraviolet beam 100 scans that area or aplurality of locations 106 thereof for stitching the member LIR to theinterior of the carrier preform P.

As an alternative embodiment, reference taken to FIG. 14 whichillustrates the same basic structure as FIG.13, with the exception ofthe application of the electromagnetic energy. In FIG. 14, the robot 105manipulates a binder spray device 120 which sprays a microwave-sensitivebinder along the area 102 and/or a matching area on the rib LIR, therobot 128 positions the rib LIR into intimate contact with the preform Pat the sprayed area and microwave energy is supplied from a robotmanipulated device 108 carrying a microwave generator 110 which iscoupled at 112 to a split waveguide 114 including an upper waveguidesection 116 and a lower waveguide section 118. As shown, the waveguidesections 116 and 118 together form a single waveguide shaped to conformto the shape of the carrier preform P with the reinforcement rib LIR inplace and some mechanism robot or the like (not shown) must be providedto open and close the waveguide 114.

Sometimes it is desirable to close the hollow structure of the preformor of the carrier preform P including any core material therein to blockfilling with resin during the following molding process. In this case,and as shown in FIGS. 1 and 15, the robot 128 or similar manipulatorpicks up a cover C and positions the same in registry with the preformP. The robot 94 and possibly additional robots may then grasp andposition a portion of the edges of the assembly, after spraying themarginal edge or flange of the preform P and/or of the cover C with amicrowave-sensitive binder resin, into a slotted waveguide 122 having anupper section 124 and a lower section 126. The carrier preform has nowbeen stitched closed and may include core material and/or one or moreinternal reinforcement ribs of the type illustrated in FIGS. 12 and 13.In addition, it may include or be manipulated and stitched to includeone or more external ribs ER of the type illustrated in FIG. 11.

FIG. 16 illustrates a similar cover stitching procedure in which thebinder spray 104 is manipulated to spray ultraviolet-sensitive binderresin along the marginal edge or flange of the preform P and/or a coverC and the cover C is manipulated into proper position and the twoelements are stitched together with an energetic stitching head 98 whichis positional by way of the gantry 96 to stitch around the entireperiphery of the assembly.

As mentioned above, the energetic basting and stitching procedures, infact all such attachment procedures, may be performed by various typesof radiating elements, including microwave, ultraviolet and electrongun.

Referring now to FIG. 17, an energetic basting station 400 isillustrated at the output of the compaction stage 3. The energeticbasting station 400, in this embodiment, comprises a gantry 42 havingthe same structure as that illustrated in FIG. 3 with the exception thatthe fiber optic wand 46 is not employed. Here, an ultraviolet laser 130is excited to emit an ultraviolet laser beam 132 for curing the binderat the spaced locations 47.

In place of the ultraviolet laser generator, an electron gun could beemployed, assuming the binder resin would be curable (free electronbonding) in response to the electron beam.

Another embodiment of energetic basting is illustrated in FIG. 18 at anenergetic basting station 4000 located at the output of the compactionstage 3. Here again, the gantry 42 is illustrated and operates in thesame manner as that of FIG. 3 to position an energetic bastingapplicator in three coordinate directions. In this embodiment, however,the source of electromagnetic energy is a source 134 of microwave energywhich is coupled to a waveguide 136 having an upper section 138 and alower section 140. The lower section 140 is carried by a member 144which is vertically movable in an actuator 146 carried by a member 140awhich is longitudinally movable in an actuator 150 carried on atransverse beam 152, mounted parallel to the beam 50, but below the webson the gantry 42.

In summary, the present invention provides a process for making rigidthree-dimensional preforms using reinforcement materials such as glassfiber webs coated with a binder resin. The webs are drawn fromrespective rolls of reinforcement material and superposed and directedsuch that they travel toward a common location at which they are guidedso as to travel parallel with respect to one another. Before becomingparallel, the superposed webs have a binder resin of electromagneticenergy-curable material applied, as by spraying, to at least one surfaceof each pair of facing surfaces and, after becoming parallel, arepressed together to distribute the binder resin and increase the contactarea thereof with the fibers of the reinforcement material. The binderresin cures in response to the application of a selected electromagneticenergy, such as microwave energy, ultraviolet energy or electron beamenergy. After being pressed together, the webs travel to an energeticbasting station where the selected electromagnetic energy is applied tospaced zones through the multilayer web structure to bind those zonesand tack the webs together so that they proceed as they were a singleweb. The electromagnetic basting may occur through the application ofthe selected energy by way of an ultraviolet wand, and ultravioletlaser, microwave via a split microwave waveguide or an electron beamgun. Next, the basted web is cut into mats having shapes eachcorresponding to a two-dimensional planar development of thethree-dimensional shape of the desired rigid three-dimensional preform.A cut mat is then transferred to a mold where it is formed into thethree-dimensional shape of the preform between complementary-shapedupper and lower molds. The molds are constructed of material which istransmissive to the selected electromagnetic energy and are operabletherewith to cause curing of the uncured binder resin remaining afterbasting of the spaced zones and to cause the shaped mat to become rigid,thus resulting in the desired rigid three-dimensional preform. At thistime, the preform may be utilized in a further molding process or may beconsidered as a carrier preform to which a subassembly or subassemblies(reinforcement elements and/or mounting members) are energeticallystitched by applying an electromagnetic energy curable binder resin to aselected location or locations, moving the subassembly into intimatecontact with the preform at those selected locations on the preformand/or on the subassembly and applying selected electromagneticradiation to those locations to cure the binder and attach thereinforcement member. These last steps may be multiplied or repeated toattach a plurality of subassemblies including a cover member whichcloses the hollow shaped of the preform to hold a core therein. Afterall of the reinforcement and/or mounting members are attached, theresulting preform may be transferred to a further molding process.

Although we have described our invention by reference to particularillustrative embodiments thereof, many changes and modifications of theinvention may become apparent to those skilled in the art withoutdeparting from the spirit and scope of the invention. We thereforeintend to include within the patent warranted hereon all such changesand modifications as may reasonably and properly be included within thescope of our contribution to the art.

We claim:
 1. Apparatus for making a rigid three-dimensional preform,comprising:means for moving a plurality of webs of fibrous reinforcingmaterial along respective paths and guiding the webs superposed suchthat they superpose coplanar to extend parallel to one another andtravel parallel to and in contact with one another; means applying anuncured electromagnetic energy-curable binder to at least one surface offacing surfaces of the webs; means for pressing the parallel contacting,moving webs together to spread the binder and increase the permeationthereof into the webs; means for locally applying electromagneticradiation into selected spaced locations of the pressed contacting websto cure the binder and thereby tack the webs together at said selectedspaced locations; means for cutting blanks of a predetermined shape fromthe webs of fibrous reinforcing material; means for forming the blankinto a desired three-dimensional shape of the preform; and means forapplying electromagnetic radiation to the shaped blank to cure theremaining uncured binder and rigidize the shaped blank into the desiredrigid three-dimensional preform.
 2. Apparatus for making rigidthree-dimensional preforms, comprising:a source of reinforcementmaterial, said source including a plurality of rolls of thereinforcement material to be dispensed from said rolls toward apredetermined location as a plurality of converging superposed webs; abinder station intermediate said source and said predetermined locationfor applying an electromagnetic energy-curable binder to at least onesurface of each pair of facing surfaces of the moving superposed webs;pressing means receiving and drawing the webs from said source andincluding guide means at said predetermined location for guiding saidplurality of moving webs to move together parallel to one another andpressing adjacent webs into intimate contact to spread the binder andimprove the permeation thereof into the webs; energetic basting meansfor receiving and tacking said plurality of moving webs together,including electromagnetic energy means for radiating and curing thebinder in spaced local zones through the superposed webs and tacking thesame together at said local zones; cutting means for receiving thetacked webs from said energetic basting means and cutting individualmats therefrom each shaped as a two-dimensional planar development ofthe desired preform; molding means including a mold operable to receiveand press the individual mats into the desired three-dimensional preformshape, and electromagnetic radiation means coupling electromagneticenergy into said mold to cure the remaining uncured binder and rigidizethe shaped structure; and material handling means for moving theindividual mats from said cutting means and into said mold.
 3. Theapparatus of claim 2 wherein:the binder station applies an ultravioletenergy-curable binder; and said electromagnetic energy means comprisesultraviolet wave generation means.
 4. The apparatus of claim 3,wherein:said ultraviolet wave generation means comprises at least oneultraviolet lamp.
 5. The apparatus of claim 2, wherein:the binderstation applies a microwave energy-curable binder; and saidelectromagnetic radiation means comprises microwave generation means. 6.The apparatus of claim 5, wherein:said electromagnetic energy meanscomprises a split waveguide coupled to said microwave generator andreceiving the superposed moving webs therethrough.
 7. Apparatus formaking a hollow rigid three-dimensional preform as a carrier preform andattaching at least one auxiliary member thereto, comprising:a source ofglass fiber reinforcement material, said source including a plurality ofrolls of the reinforcement material which is dispensed toward apredetermined location from said rolls as a plurality of convergingsuperposed webs; binder applying means intermediate said source and saidpredetermined location for applying an ultraviolet energy-curable binderto at least one surface of each pair of facing surfaces of the movingsuperposed webs; pressing means receiving and drawing said websincluding guide means at said predetermined location for guiding saidplurality of moving webs to move together parallel to one another andpressing adjacent ones of the webs into intimate contact to spread thebinder resin and improve contact thereof with the fibers of the webs;energetic basting means for receiving and tacking said plurality ofmoving webs together, including ultraviolet radiation means forradiating and curing spaced local zones through the superposed webs ofglass fiber reinforcement material thereby tacking the same together insaid spaced local zones; cutting means for receiving the tacked websfrom said energetic basting means and cutting an individual multilayermat therefrom shaped as a two-dimensional planar development of thedesired preform; molding means including a mold operable to receive andpress the individual mats into the desired three-dimensional preformshape, and ultraviolet radiation means coupling ultraviolet radiationinto said mold to cure the remaining uncured binder resin and rigidizethe molded structure; material handling means for moving the individualmats from said cutting means and into said mold; and energetic stitchingmeans for attaching the at least one auxiliary member to the preform,said material handling means comprising material manipulation means fororienting the preform into a predetermined position, and said energeticstitching means comprising further binder applying means for applyingultraviolet energy-curable binder to at least one selected location onthe preform, means for moving the at least one auxiliary member, meansfor moving the at least one auxiliary member into a desired position andinto intimate contact with the preform at the least one selectedultraviolet radiation to said at least one selected area to cure thebinder thereat and attach the at least one auxiliary member to thepreform.
 8. Apparatus for making a rigid three-dimensional reinforcedpreform comprising:means forming a rigid preform of a desired shape;means applying a binder curable by the application of ultraviolet energyto the preform; means applying a reinforcement member to the preform;and means applying ultraviolet energy to the binder at predeterminedselected locations to stitch the reinforcement member to the preformjoining the preform and reinforcement member rigidly.
 9. Apparatus formaking a rigid three-dimensional reinforced preform constructed inaccordance with claim 8:wherein said means for applying binder appliesthe binder at predetermined selected locations to the preform; and saidmeans for applying ultraviolet energy applies the energy to the binderat said locations to stitch the reinforcement member to the preform. 10.Apparatus for making a rigid three-dimensional reinforced preformcomprising:means forming a rigid preform of a desired shape; meansapplying a binder curable by the application of electromagneticradiation to the preform; means applying a reinforcement member to thepreform; and means applying electromagnetic radiation the binder atpredetermined select locations to stitch the reinforcement member to thepreform joining the preform and reinforcement member rigidly. 11.Apparatus for making a rigid three-dimensional reinforced preformconstructed in accordance with claim 10:wherein said means for applyingbinder applies the binder at predetermined select locations to thepreform; and said means for applying electromagnetic radiation appliesthe radiation to the binder at said locations to stitch thereinforcement member to the preform.
 12. An apparatus for the attachmentof members to preforms comprising the combination:means for applying anelectromagnetic energy-curable binder at a binder area to at least oneof the areas of a carrier preform or to a member where the preform andmember are to be attached; means positioning the preform and member inan oriented location into intimate contact at said binder area; andpositioning an electromagnetic stitcher having a microwave energy outputand directing electromagnetic energy to said binder area toenergetically stitch and attach said preform and said member.
 13. Anapparatus for the attachment of a member to a preform constructed inaccordance with claim 12:wherein said applying means applies anultraviolet energy-curable binder and said stitcher has an ultravioletenergy output and directs ultraviolet energy to said binder area toenergetically stitch and attach said preform and said member.
 14. Anapparatus for the attachment of a member to a preform constructed inaccordance with claim 13:wherein said applying means directs said binderin a spray to apply said binder to the binder area.
 15. An apparatus forthe attachment of a member to a preform constructed in accordance withclaim 13:wherein said applying means applies the binder at a pluralityof binder areas between the preform and the member.
 16. An apparatus forthe attachment of a member to a preform constructed in accordance withclaim 13:wherein said stitcher has a movable support to scan the binderarea for energetically stitching and attaching the member to saidpreform.
 17. An apparatus for the attachment of a member to a preformconstructed in accordance with claim 13:wherein said stitcher is shapedto conform to the shape of the carrier preform.
 18. An apparatus for theattachment of a member to a preform constructed in accordance with claim13:wherein said applying means applies said binder along a marginal edgeof the carrier preform.